kingofdodge7131

Hey guys quick question. Looking at the exhaust vents on my furnace it goes horizontal then where it tees in to go up there is a actual t. It has 3 " or so that are below the exhaust piping and then that's blocked off. I saw this at was mart as well. What's the purpose of it? I'm trying to attach a pic now

chaikwa

Well I don't know what kind of furnace you're referring to, gas. oil or whatever, but by the way you describe it, it sounds like a cleanout. Remove the blockage on the bottom of the tee and when you clean the pipe, everything will just fall out.

One of your sentences, "I saw this at was mart as well", kind of confuses me tho as I don't know what you were trying to say. You've seen this somewhere else before?

kingofdodge7131

Here is the photo

chaikwa

Yep, I'd say it's a cleanout. The tee may be code regardless of what kind of furnace it is but I really don't know. I have the same set-up on my oil furnace I installed here at the shop, specifically so I COULD clean out the pipe.

j_martin

I have a kink in my neck from looking at the sideways picture.

It's a cleanout. The other purpose is if something gets dropped into the chimney, (Dead bird, grasshopper, falling meteor) it'll tend to collect in the T instead of getting funneled into the furnace where it might cause real trouble.

Shovelhead

Does this help?

kingofdodge7131

Thats what i had thought, Had a debate with a customer, I figured it was for a clean out, drip pan, whatever you wanna call it so debris stay out of the furnace and piping, Customer told me it had something to do with the air flow and caused a draft. My home one does not have this option, They are all Natrual gas furnaces btw. but nice to know its there

kingofdodge7131

oh yeah, pic was with the wifes new IPAD never wanted one, but its nice, i think ill get a windows version or android. I cant do anything due to it not being flash compatible. i had to email that picutre to my phone to put it on the site, stupid

kingofdodge7131

oh yeah, pic was with the wifes new IPAD never wanted one, but its nice, i think ill get a windows version or android. I cant do anything due to it not being flash compatible. i had to email that picutre to my phone to put it on the site the story of "Apple" is amazing but it seems to me its more of a sheep following sheep thing than the ability to use a product making htme well

j_martin

Sometimes when I have too much draft to a gas appliance that wants "atmospheric" draft, I'll throw a T in the line and leave the bottom leg open. It has the same effect as the bell shaped thingie on a water heater.

Bark

Cant believe it. Once again I actually learned something useful on DTR.

Jim Lane

Draft Hood or Draft Diverter

Believe it or not I have replace water heater in houses where they had plumbed the heater directly to the flue pipe, no draft hood.
as long as there are Do It Yourselfers I can always make money.

Jim

j_martin

I was tired when I typed that. Couldn't scrape the nomenclature out'n my head. Thanks.

Don't rankle on just the diy crowd.

I trouble shot a Tjernlund commercial multifuel hot air furnace in the local Catholic church. In cold weather it would blow out all the time, in either fuel. It was also in the same room as the water service entrance and the water meter would freeze up and break every time it did it.

The certified furnace company had changed out the alarm'd flame control for one without an alarm contact, so when it flamed out the draft would keep running and the cold air draft damper on the wall would stay open. First thing I did was change that out for the right control.

It was a direct vent unit piped into a 40' high brick chimney with no draft control on it at all. It had .14" of draft sucking the flame right off the burner in gas. Oil would run, but the flame sensor was missing a lens, and so was marginal on current.

I had to tell the Tjernlund engineers to take a leap. They would not give me permission to put a draft damper in it. That draft damper fixed it.

chaikwa

Well let's not just limit it to the installation personnel. Years ago, some of you may remember when we had a natural gas shortage. (This was in the northeast, but may have been nation-wide, I don't remember) I was working for a large computer place in maintenance, and they had 4 HUGE boilers that were gas OR oil fired. We switched over to the oil side because we couldn't get enough gas into the units to make fire, much less hot water. They'd run on oil for about 30 seconds then cut out on safety, like they didn't see the fire. The cad cell eyes tested out fine but we replaced them anyway. Still wouldn't stay running. Finally, after multiple factory techs and reps had exhausted their 'extensive' knowledge of their units, we learned form one of the original design engineers that they needed to see full fire on a gas burn before they could be switched over to oil and stay running. There's smarts for ya!

j_martin

My dad had a saying about "engineers" that designed such stuff. Usually in an automotive context.

"You have to feel sorry for them. They will spend eternity in Hell trying to reach an adjustment that can't be reached."